Band structure of 235 U

Over a period of several years we have performed three separate experiments at Lawrence Berkeley National Laboratory's 88-Inch Cyclotron in which 235U (thick target) was Coulomb-excited. The program involved stand-alone experiments with Gammmasphere and with the 8pi Spectrometer using 136Xe beams at 720 MeV, and a CHICO-Gammasphere experiment with a 40Ca beam at 184 MeV. In addition to extending the known negative-parity bands to high spin, we have assigned levels in some seven positive-parity bands which are in some cases (e.g., [631]1/2, [624]7/2, and [622]5/2) strongly populated by E3 excitation. The CHICO data have been analyzed to extract E2 and E3 matrix elements from the observed yields. Additionally, many M1 matrix elements could be extracted from the γ-ray branching ratios. A number of new features have emerged, including the unexpected attenuation of magnetic transitions between states of the same Nilsson multiplet, the breakdown of Coriolis staggering at high spin, and the effect of E3 collectivity on Coriolis interactions

Vibrational and rotational sequences in 101 Mo and 103,4 Ru studied via multinucleon transfer reactions

The near yrast states of 101 Mo and 103,104 Ru have been studied following their population via heavy ion multinucleon transfer reactions between a 136 Xe beam and a thin, self supporting 100 Mo target. The ground state sequence in 104 Ru can be understood as demonstrating a simple evolution from a quasi vibrational structure at lower spins to statically deformed, quasi rotational excitation involving the population of a pair of low Omega h11 2 neutron orbitals. The effect of the decoupled h11 2 orbital on this vibration to rotational evolution is demonstrated by an extension of the E GOS prescription to include odd A nuclei. The experimental results are also compared with self consistent Total Routhian Surface calculations which also highlight the polarising role of the highly aligned neutron h11 2 orbital in these nucle

Outcomes of Radiofrequency Ablation as First-Line Therapy for Hepatocellular Carcinoma less than 3 cm in Potentially Transplantable Patients

© 2019 European Association for the Study of the Liver Background & Aims: Radiofrequency ablation (RFA) is an effective treatment for single hepatocellular carcinoma (HCC) ≤3 cm. Disease recurrence is common, and in some patients will occur outside transplant criteria. We aimed to assess the incidence and risk factors for recurrence beyond Milan criteria in potentially transplantable patients treated with RFA as first-line therapy. Methods: We performed a retrospective cohort study of potentially transplantable patients with new diagnoses of unifocal HCC ≤3 cm that underwent RFA as first-line therapy between 2000-2015. We defined potentially transplantable patients as those aged 2 cm). Competing risks Cox regression was used to identify predictors of recurrence beyond Milan criteria. Results: We included 301 patients (167 HCC ≤2 cm and 134 HCC >2 cm). Recurrence beyond Milan criteria occurred in 36 (21.6%) and 47 (35.1%) patients in the HCC ≤2 cm and the HCC >2 cm groups, respectively (p = 0.01). The 1-, 3- and 5-year actuarial survival rates after RFA were 98.2%, 86.2% and 79.0% in the HCC ≤2 cm group vs. 93.3%, 77.6% and 70.9% in the HCC >2 cm group (p = 0.01). Tumor size >2 cm (hazard ratio 1.94; 95% CI 1.25–3.02) and alpha-fetoprotein levels at the time of ablation (100–1,000 ng/ml: hazard ratio 2.05; 95% CI 1.10–3.83) were found to be predictors of post-RFA recurrence outside Milan criteria. Conclusion: RFA for single HCC ≤3 cm provides excellent short- to medium-term survival. However, we identified patients at higher risk of recurrence beyond Milan criteria. For these patients, liver transplantation should be considered immediately after the first HCC recurrence following RFA. Lay summary: Radiofrequency ablation and liver transplantation are treatment options for early stages of hepatocellular carcinoma (HCC). After ablation some patients will experience recurrence or metastatic spread of the initial tumor or may develop new tumors within the liver. Despite close follow-up, these recurrences can progress rapidly and exceed transplant criteria, preventing the patient from receiving a transplant. We identified that patients with HCC >2 cm and higher serum alpha-fetoprotein are at greater risk of recurrence beyond the transplant criteria. These data suggest that liver transplantation should be considered immediately after the first HCC recurrence for these patients

Collectivity and Configuration Mixing in \u3csup\u3e186,188\u3c/sup\u3ePb and \u3csup\u3e194\u3c/sup\u3ePo

Lifetimes of prolate intruder states in 186Pb and oblate intruder states in 194Po have been determined by employing, for the first time, the recoil-decay tagging technique in recoil distance Doppler-shift lifetime measurements. In addition, lifetime measurements of prolate states in 188Pb up to the 8+state were carried out using the recoil-gating method. The B(E2) values have been deduced from which deformation parameters lβ2l = 0.29(5) and lβ2l = 0.17(3) for the prolate and the oblate bands, respectively, have been extracted. The results also shed new light on the mixing between different shapes

Collectivity and configuration mixing in 186,188Pb and 194Po

Lifetimes of prolate intruder states in 186Pb and oblate intruder states in 194Po have been determined by employing, for the first time, the recoil-decay tagging technique in recoil distance Doppler-shift lifetime measurements. In addition, lifetime measurements of prolate states in 188Pb up to the 8+ state were carried out using the recoil-gating method. The B(E2) values have been deduced from which deformation parameters |β2|=0.29(5) and |β2|=0.17(3) for the prolate and the oblate bands, respectively, have been extracted. The results also shed new light on the mixing between different shapes

Spectroscopy around 36^{36}Ca

Expérience GANILInternational audienceAn experiment was performed to study excited states in neutron-deficient nuclei around Ca. A one-neutron knockout reaction was used to produce $^{36}$Ca ions from a $^{37}$Ca secondary beam, and in-beam $\gamma$-rays were measured. The $2^+$ energy in $^{36}$Ca is compared to the mirror nucleus $^{36}$S to deduce information on the isospin dependence of the nuclear force near the proton drip line. The energy of the first excited $2^+$ state in $^{36}$Ca and the cross section for the 1-neutron knock-out reaction from $^{37}$Ca at $\sim$ 45 · AMeV were obtained. Furthermore, for two other $T_z$ = −2 nuclei, $^{28}$S and $^{32}$Ar, the de-excitation of the first $2^+$ state has been observed

Lifetimes of intruder states in 186 Pb, 188 Pb and 194 Po

Lifetimes of prolate intruder states in 186Pb and 188Pb and oblate intruder states in 194Po have been determined through recoil distance Doppler-shift lifetime measurements. Deformation parameters of | β2 | = 0.29 (5) and | β2 | = 0.17(3) have been ext

Single step links of the superdeformed band in Pb-194:A measure of the absolute excitation energy, spin and parity of the superdeformed states

The EUROGAM array has been used to investigate the decay out of the yrast superdeformed (SD) band in Pb-194. Six single step decays from the lowest observed SD slates to low-lying states at normal deformation (ND) have been identified. From this observation, the excitation energy of the SD band in Pb-194 is established at 4877 +/- 1.5 keV for the 6(+) SD state. The most probable spins and parities of all members of the SD band are also deduced assuming that the SD states have even spin and positive parity

Linear polarization measurement of interband transitions in superdeformed (190)Hg: model-independent evidence for octupole vibrational structures

The linear polarization of γ rays between excited and yrast superdeformed (SD) states in 190Hg was measured using the four-element CLOVER detectors of the EUROBALL IV γ-ray spectrometer. This measurement shows in a model-independent way that the interband transitions which compete with the highly collective in-band quadrupole transitions are largely enhanced electric dipoles. Not only do these results represent the first measurement of the multipolarity of transitions between different SD states, but they also provide strong evidence for the interpretation of the structures in the SD minimum of the A∼190 region in terms of octupole excitations.A. Korichi, A. N. Wilson, F. Hannachi, A. Lopez-Martens, M. Rejmund, C. Schück, Ch. Vieu, G. Chmel, A. Görgen, H. Hübel, D. Rossbach, S. Schönwasser, M. Bergström, B. M. Nyakó, J. Timár, D. Bazzacco, S. Lunardi, C. Rossi-Alvarez, P. Bednarczyk, N. Kintz, S. Naguleswaran, A. Astier, D. M. Cullen, J. F. Sharpey-Schafer, T. Lauritsen, and R. Wadswort